I'm using the Google Drive API to copy a form, among other files, from account A to a parent folder on account B. The form is successfully copied to the parent folder but a second copy of the form, named "Copy of [form name]", is left in the root folder of the destination account. I am copying all file types, but this seems to happen only with forms, though not every form. This is happening with the Python library in my own script and also, less predictably, through the UI at https://developers.google.com/drive/v2/reference/files/copy.
This issue is mentioned in the answer to Copy file into a specific parent folder with Google Drive API?, but there it is not limited to forms apparently.
Can anyone explain or tell how to prevent the unwanted copy on the root?